Pest-resistant transgenic crops are continually being developed to allow for increased crop yields while reducing the amount of pesticides required. However, the potential for pest resistance to the transgenic crops is widely recognized, and the agricultural community is anxious to establish protocols by which the emergence of completely unsusceptible pest populations can be significantly delayed or prevented.
One way to slow the rate at which pests evolve resistance to transgenic crops is to ensure the presence of a refuge where susceptible pests are not exposed to the pesticide. In theory, the adult pests which emerge from the refuge environment will disperse and breed with any pests which emerge from the recombinant fields, and if any of the insects which emerge from the recombinant fields have developed a level of resistance to the recombinant pesticidal proteins, the availability of that trait in the subsequent generations will be diluted, thereby reducing or delaying the onset of the emergence of a race which will be totally resistant to the recombinant plant.
Refuge areas may consist of portions of the crop of interest that are untreated (i.e., structured refuge) or other suitable crop and weedy hosts of the pest (i.e., alternative host refuge or natural refuge). Evaluating the refuge available for a pest that is capable of developing on multiple host plant species requires some means of evaluating the portion of the insect population that exists on the different potential hosts.
In today's regulatory environment, obtaining the approval of an appropriate regulatory agency for commercialization of a recombinant plant requires that a percentage of the entire crop that is planted containing a recombinant trait be planted as a refuge of non-recombinant or non-transgenic crops on a farm-by-farm basis. Refuge requirements increase farmers' labor and financial expenses, and are difficult to police. The added labor for planting and segregating the refuge and the likely lower yields within the refuge as a result of greater insect infestation are a disincentive for the farmer to comply with the regulatory requirements.
Thus, there remains a need for methods of determining the feeding habits and feeding history of animals, and particularly pests, such that more effective refuge areas can be determined or designed. Accordingly, it would be desirable to be able to screen or fingerprint an animal or population of animals in a manner that would readily identify patterns of movement and feeding habits or history.